From mahnaz at stanford.edu  Fri Apr  8 07:51:51 2011
From: mahnaz at stanford.edu (Mahnaz Mansourpour)
Date: Fri, 08 Apr 2011 07:51:51 -0700
Subject: SVG Coat 1 Scheduled Downtime-
Message-ID: <4D9F2107.8070503@stanford.edu>

Hello Litho Users....

     The Litho staff has scheduled and reserved time on Monday 4/11 and Wednesday 4/13 from 8:00am to 12:00 noon to work on the thick resist process on SVG Coater #1. During this time the track will be down and unavailable to lab users. We will not be shutting down track #2 but we would appreciate if you could delay your SVG Coat processing til the afternoon. This will allow the Litho team access to the back track as a support tool during troubleshooting and will eliminate traffic and congestion around this area. We will certainly accommodate your needs if you have a few wafers to process but would greatly appreciate your support in this effort. Thanks in advance for your support and we apologize for the inconvenience.

     Regards... The Litho Team



From gsosa at stanford.edu  Thu Apr 14 16:49:08 2011
From: gsosa at stanford.edu (Gary J Sosa)
Date: Thu, 14 Apr 2011 16:49:08 -0700 (PDT)
Subject: Update on thick resist work
In-Reply-To: <2146899530.413884.1302823065258.JavaMail.root@zm08.stanford.edu>
Message-ID: <2047993246.415592.1302824948402.JavaMail.root@zm08.stanford.edu>

Hi All

   Here is an update of the work performed on Monday and Wednesday with respect to thick resist processing. We created several recipes with different methods of applying the photoresist. This included a center to edge technique, center dispense, center dispense with no spin. For each recipe, there were variations of dispense arm timing, pump didpense rate/volume, speed of wafer during dispensing. The results were very mixed but still showed the unusual artifact in the center of the wafer which has large impact on overall thickness uniformity. The artifact seems to appear when the wafer goes into the high speed step for casting the resist thickness. The artifact appears as a tiny dot that grows to the size of a quarter or larger during the casting step. Created a program that slowly ramped the speed up to 3500 RPM in 500 RPM increments. This did not solve the problem and overall spin quality suffered. We will continue to work on the issue and update you as we go along.

     Thanks.. The Litho Team